| EMAG2: Earth Magnetic Anomaly Grid (2-arc-minute resolution) |
 |
EMAG2 is a global Earth Magnetic Anomaly Grid compiled from satellite, ship, and airborne
magnetic measurements. It is a significant update of our previous candidate grid for
the World Digital Magnetic Anomaly Map. The resolution has been improved from 3 arc-minutes
to 2 arc-minutes, and the altitude has been reduced from 5 km to 4 km above the geoid.
Additional grid and track line data have been included, both over land and the oceans.
Wherever available, the original shipborne and airborne data were used instead of
precompiled oceanic magnetic grids. Interpolation between sparse track lines in the
oceans was improved by directional gridding and extrapolation, based on oceanic crustal
age model. The longest wavelengths (>330 km) were replaced with the latests CHAMP
satellite magnetic field model MF6. |
|
![How can I download or order the data?](javascript:getTemplate('<table> <tr> <td> <table class="resultTable"><tr> <th>Online Access</th> <td><a href="https://www.ncei.noaa.gov/metadata/geoportal/rest/metadata/item/gov.noaa.ngdc.mgg.geophysical_models:EMAG2/html">Metadata Landing Page</a><br/><br/><br/><a href="http://geomag.colorado.edu/emag2-earth-magnetic-anomaly-grid-2-arc-minute-resolution.html">EMAG2 Home Page</a><br/><br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_poster_V2.pdf">EMAG2 Full Resolution Map poster</a><br/>PDF of Full Resolution Map of EMAG2 as a poster<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_poster_V2.jpg">EMAG2 Full Resolution Map poster</a><br/>JPG of Full Resolution Map of EMAG2 as a poster.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_image_V2.jpg">EMAG2 Full Resolution Map image</a><br/>JPG of Full Resolution Map of EMAG2 as an image.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/emag2.pdf">EMAG2: A 2-arc-minute resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne and marine magnetic measurements</a><br/>Preprint of manuscript "EMAG2: A 2-arc-minute resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne and marine magnetic measurements", submitted for publication to Geochem. Geophys. Geosyst.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2.kmz">Google Earth</a><br/>Plugin for Google Earth. Requires installation of Google Earth.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_V2.xyz.gz">XYZ/Zip</a><br/>EMAG2 ASCII grid of the magnetic total intensity at 4km above WGS84 ellipsoid.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_V2.tif">GIS TIFF</a><br/>A georeferenced TIFF (GeoTIFF) with a resolution of 2-arc-minutes, which can be opened by ESRI ArcGIS or any other GIS application. The values (nT) are stored as 32-bit floating point.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_V2.grd">GMT Grid</a><br/>A GMT (Generic Mapping Tools) compatible netCDF grid with resolution of 2-arc-minutes. The values (nT) are stored as 32-bit floating point.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_image_V2.tif">Color-relief</a><br/>A 24-bit RGB georeferenced TIFF (GeoTIFF) color-relief visualization of the EMAG2 grid, which can be opened by ArcGIS or any other GIS application.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_no_directional_gridding_2009-01-06.xyz.gz">XYZ/zip</a><br/>EMAG2 (Version 2.0) ASCII grid of the magnetic total intensity at 4km above WGS84 ellipsoid. This version was produced without directional gridding. Therefore, it has much sparser coverage but reflects more closely the actual measurements.<br/><br/></td> </tr><tr> <th>Data Formats</th> <td> <dl><dt>PDF</dt><dd> Version:Version 2</dd><dd> Format Specification:Full Resolution Map of EMAG2 as a poster</dd><br/><dt>JPG</dt><dd> Version:Version 2</dd><dd> Format Specification:Full Resolution Map of EMAG2 as a poster</dd><br/><dt>JPG</dt><dd> Version:Version 2</dd><dd> Format Specification:Full Resolution Map of EMAG2 as an image</dd><br/><dt>Article</dt><dd> Version:Version 2</dd><dd> Format Specification:Preprint of manuscript "EMAG2: A 2-arc-minute resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne and marine magnetic measurements", submitted for publication to Geochem. Geophys. Geosyst.</dd><br/><dt>Google Earth</dt><dd> Version:Version 2</dd><dd> Format Specification:Plugin for Google Earth. Requires installation of Google Earth. See also https://productforums.google.com/forum/?fromgroups#!msg/gec-dynamic-data-layers/yYsaTFnIzYQ/RVwprs5WhPQJ[1-25]</dd><br/><dt>XYZ/Zip</dt><dd> Version:Version 2</dd><dd> Format Specification:ASCII grid of the magnetic total intensity at 4km above WGS84 ellipsoid.</dd><br/><dt>GIS TIFF</dt><dd> Version:Version 2</dd><dd> Format Specification:A georeferenced TIFF (GeoTIFF) with a resolution of 2 arc-minutes, which can be opened by ESRI ArcGIS or any other GIS application. The values (nT) are stored as 32-bit floating point.</dd><br/><dt>GMT Grid</dt><dd> Version:Version 2</dd><dd> Format Specification:A GMT (Generic Mapping Tools) compatible net CDF grid with resolution of 2-arc-minutes. The values (nT) are stored as 32-bit floating point.</dd><br/><dt>GeoTIFF</dt><dd> Version:Version 2</dd><dd> Format Specification:Color-relief: A 24-bit RGB georeferenced TIFF (GeoTIFF) color-relief visualization of the EMAG2 grid, which can be opened by ArcGIS or any other GIS application. The color scale legend is at http://geomag.colorado.edu/images/EMAG2_scale.png</dd><br/></dl> </td> </tr><tr> <th>Order Details</th> <td><b>Cost: </b>In most cases, electronic downloads of the data are free. However, fees may apply for custom orders, data certifications, copies of analog materials, and data distribution on physical media.<br/><b>Instructions: </b>Contact NCEI for other distribution options and instructions.</td> </tr></table></td> </tr> </table>')){kind=link}
![What are the URLs and other online resources associated with this data set?](javascript:getTemplate('<table> <tr> <td> <table class="resultTable"><tr> <th>Information</th> <td><a href="https://epsg.org/crs_4326/WGS-84.html">WGS 84</a><br/>GML of World Geodetic System 1984 coordinate reference system.<br/><br/><a href="https://forum.earthdata.nasa.gov/app.php/tag/GCMD%2BKeywords">GCMD Keyword Forum Page</a><br/>Global Change Master Directory (GCMD). 2024. GCMD Keywords, Version 19. Greenbelt, MD: Earth Science Data and Information System, Earth Science Projects Division, Goddard Space Flight Center (GSFC), National Aeronautics and Space Administration (NASA). URL (GCMD Keyword Forum Page): https://forum.earthdata.nasa.gov/app.php/tag/GCMD+Keywords<br/><br/><a href="https://www.ncei.noaa.gov/contact">NCEI Contact Information</a><br/>Information for contacts at NCEI.<br/><br/><a href="https://www.ncei.noaa.gov/metadata/geoportal/rest/metadata/item/gov.noaa.ngdc.mgg.geophysical_models:EMAG2/html">Metadata Landing Page</a><br/><br/><br/><a href="http://geomag.colorado.edu/emag2-earth-magnetic-anomaly-grid-2-arc-minute-resolution.html">EMAG2 Home Page</a><br/><br/><br/></td> </tr><tr> <th>Search</th> <td><a href="https://epsg.org/home.html">European Petroleum Survey Group Geodetic Parameter Registry</a><br/>Registry that accesses the EPSG Geodetic Parameter Dataset, which is a structured dataset of Coordinate Reference Systems and Coordinate Transformations.<br/><br/></td> </tr><tr> <th>Download</th> <td><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_poster_V2.pdf">EMAG2 Full Resolution Map poster</a><br/>PDF of Full Resolution Map of EMAG2 as a poster<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_poster_V2.jpg">EMAG2 Full Resolution Map poster</a><br/>JPG of Full Resolution Map of EMAG2 as a poster.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_image_V2.jpg">EMAG2 Full Resolution Map image</a><br/>JPG of Full Resolution Map of EMAG2 as an image.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/emag2.pdf">EMAG2: A 2-arc-minute resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne and marine magnetic measurements</a><br/>Preprint of manuscript "EMAG2: A 2-arc-minute resolution Earth Magnetic Anomaly Grid compiled from satellite, airborne and marine magnetic measurements", submitted for publication to Geochem. Geophys. Geosyst.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2.kmz">Google Earth</a><br/>Plugin for Google Earth. Requires installation of Google Earth.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_V2.xyz.gz">XYZ/Zip</a><br/>EMAG2 ASCII grid of the magnetic total intensity at 4km above WGS84 ellipsoid.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_V2.tif">GIS TIFF</a><br/>A georeferenced TIFF (GeoTIFF) with a resolution of 2-arc-minutes, which can be opened by ESRI ArcGIS or any other GIS application. The values (nT) are stored as 32-bit floating point.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_V2.grd">GMT Grid</a><br/>A GMT (Generic Mapping Tools) compatible netCDF grid with resolution of 2-arc-minutes. The values (nT) are stored as 32-bit floating point.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_image_V2.tif">Color-relief</a><br/>A 24-bit RGB georeferenced TIFF (GeoTIFF) color-relief visualization of the EMAG2 grid, which can be opened by ArcGIS or any other GIS application.<br/><br/><a href="http://geomag.colorado.edu/images/EMAG2/EMAG2_no_directional_gridding_2009-01-06.xyz.gz">XYZ/zip</a><br/>EMAG2 (Version 2.0) ASCII grid of the magnetic total intensity at 4km above WGS84 ellipsoid. This version was produced without directional gridding. Therefore, it has much sparser coverage but reflects more closely the actual measurements.<br/><br/></td> </tr><tr> <th>Unknown Function</th> <td><a href="http://geomag.org/info/Smaus/Doc/emag2.pdf">http://geomag.org/info/Smaus/Doc/emag2.pdf</a><br/><br/></td> </tr><tr> <th>Unknown Function</th> <td><a href="http://geomag.org/info/Smaus/Doc/wdmam.pdf">http://geomag.org/info/Smaus/Doc/wdmam.pdf</a><br/><br/></td> </tr><tr> <th>Unknown Function</th> <td><a href="http://geomag.org/info/Smaus/Doc/emag2.pdf">http://geomag.org/info/Smaus/Doc/emag2.pdf</a><br/><br/></td> </tr><tr> <th>Unknown Function</th> <td><a href="http://geomag.org/info/Smaus/Doc/wdmam.pdf">http://geomag.org/info/Smaus/Doc/wdmam.pdf</a><br/><br/></td> </tr><tr> <th>Unknown Function</th> <td><a href="http://geomag.org/info/Smaus/Doc/wdmam.pdf">http://geomag.org/info/Smaus/Doc/wdmam.pdf</a><br/><br/></td> </tr><tr> <th>Unknown Function</th> <td><a href="http://geomag.org/info/Smaus/Doc/emag2.pdf">http://geomag.org/info/Smaus/Doc/emag2.pdf</a><br/><br/></td> </tr></table> </td> </tr> </table>')){kind=link}